Islamic Law

Overall, the main focus of Muslim jurists has been the interpretation of scripture. Classical Sunni Islamic jurisprudence has at its heart a theory of four "roots," or bases, of the law, generally listed as (1) the Koran, (2) the Sunna of the Prophet Muhammad, (3) consensus (ijma'), and (4) legal analogy (qiyas). The Koran is granted pride of place as a legal source, yet many do not realize how little of the law is based on the text of the Koran itself. Muslim jurists reckoned that only five hundred verses of the Koran, about one-thirteenth of the entire text, have legal content. A genre of legal literature styled Ayat al-ahkam ("The Verses of Legal Rulings") developed that was a commentary on these verses in particular, extracting the legal content. Of these verses, many are not very specific, such as the many commands to hold prayer and give alms that do not specify how, when, and where to perform these actions.

In addition to the Koran, early jurisprudence relied on Sunna, which seems to have originally meant the general or time-honored usage of the community, and ra'y, which at this stage meant "sound opinion" or "considered opinion." With the work of al-Shafi'i, and generally for Sunnis in the course of the ninth century, it became standard theory that there was not one scripture in Islam, but actually two. The definition of Sunna narrowed to refer to the usage of the Prophet, and then further narrowed to mean "the usage of the Prophet as established by hadith," oral reports concerning the Prophet's statements and behavior transmitted from the Companions, early Muslims who were eyewitnesses of the Prophet's mission. These reports were gathered and published in collections arranged according to the Companion transmitters (musnad), or in collections arranged for easy reference by jurists according to the standard chapters of the law (sunan). Six collections, dating from the middle to late ninth century, came to be recognized as more or less canonical by Sunni Muslims of all madhhab s: the Sahih s of al-Bukhari (d. 870), Muslim (d. 875), and al-Tirmidhi (d. 892), and the Sunan of Ibn Majah (d. 886), Abu Dawud (d. 888), and al-Nasa'i (d. 915). In the ninth and tenth centuries, the relative importance of hadith as a body of scripture was highly contested. Some rationalist jurists threw it out completely; most rationalists restricted the use of individual reports severely, setting very stringent requirements for establishing its authenticity. Many traditionalists, on the other hand, based their understanding of the law almost entirely on hadith reports and sought thereby to emulate the Prophet's sunna, or exemplary behavior, as closely as possible, even in everyday matters such as trimming one's mustache and letting one's beard grow long, or using a miswak twig as a sort of toothbrush. They set out to avoid all innovations, bid'a in opposition to sunna, which could lead one into error. Even these traditionalist scholars realized that many hadith reports were forged: some hadiths spoke for and against sectarian and other theological positions that had only arisen generations after the Prophet. Others contained translations of Bible verses or other Jewish or Christian lore. They devised criteria for establishing the authenticity of hadith reports, but most of these were formal, probabilistic criteria, based on examination of the authorities in the chain of transmission (isnad) of the hadith report. If they were all known to be reliable and each could have met the preceding person in the chain, then the report was considered formally reliable, even if the text itself was recognized to be odd.

In the genre of usul al-fiqh, Islamic jurisprudence developed sophisticated scriptural hermeneutics, focusing on the interpretation of God's address (khitab Allah) to mankind, in which He conveyed the law. Particular attention was paid to commands (awamir) and prohibitions (nawahi) in the text, for they establish obligations and set up legal boundaries. Several concepts were developed to cope with apparent contradictions in the text, including abrogation, according to which a later prooftext canceled out the legal effect of an earlier prooftext, the distinction between general and particular prooftexts, which allowed jurists to distinguish the intended audience or set of legal agents to which a particular command was addressed. Over the centuries, the discussions of these topics grew more and more elaborate and linguistically sophisticated, anticipating a number of theories of modern linguistics and philosophy by many centuries.

The third "source" of the law according to classical Sunni jurisprudence was consensus, usually defined as "the unanimous agreement of legal authorities of a given generation on a particular legal." This has often been confused with popular opinion, but is in essence the agreement of the community of interpretation constituted by qualified master jurists, after debate has subsided. The existence of consensus is established through the absence of dissent. The legal questions subject to consensus, together with the disputed questions, on which a number of authoritative variant opinions are held, form the range of orthodox opinion.

The fourth "source" of the law has been variously designated as qiyas ("legal analogy") or ijtihad ("exhaustive investigation"). They both came about in an attempt to eschew ra'y ("considered opinion") as a source of the law and to tie elaboration of the law more closely to scripture. By the tenth century, and particularly in traditionalist circles, ra'y came to take on the pejorative meaning "completely unfounded or idiosyncratic opinion," as opposed to its early usage. All four Sunni madhhab s eventually renounced ra'y and accepted qiyas. Qiyas, in its simplest form, is an analogy tying the ruling of Y to the ruling of X based on a crucial similarity, termed the 'illa ("cause") of the ruling. For example, it is established from the Koranic text that drinking alcoholic beverages is forbidden, but there are no scriptural texts that apply to other drugs, such as hashish or opium. If jurists could show (1) that God declared drinking alcoholic beverages forbidden specifically because they intoxicate and (2) that hashish and opium intoxicate in a manner similar to alcohol, then the consumption of hashish or opium should also be forbidden. The jurists of the short-lived Zahiri madhhab rejected qiyas altogether, arguing that it is impossible for humans to assign a cause to God's legal declarations without explicit designation in scripture. To do so is to usurp God's legislative power. Qiyas also came to serve as a general rubric encompassing a number of logical arguments, many of which were not actually based on analogy, including reductio ad absurdum, a fortiori, and other logical arguments.

Ijtihad (literally, "effort") is the term used to describe the process of legal interpretation undertaken by a qualified expert in jurisprudence. Such an expert is termed a mujtahid and is forbidden from adopting the opinions of other experts on authority (taqlid). Only a layman, or a jurist who is not fully qualified, is permitted to perform taqlid. A great deal of controversy surrounds the term ijtihad; it was until recently commonplace to claim that "the gate of ijtihad" was closed long ago, as early as the ninth or tenth century, and that from that time forward, "independent" interpretation was forbidden. This is not true. Those who claimed that the gate of ijtihad was closed meant that it was forbidden or impossible to establish a new legal madhhab, not that there was a moratorium on independent thought. Manuals of jurisprudence throughout the middle ages and up until the present have stressed the necessity of performing ijtihad on the part of the qualified jurist, and Muslim jurists have been addressing novel issues in the law and coming up with new interpretations throughout history. Nevertheless, it is true that many jurists felt that their interpretative leeway had narrowed considerably by the late middle ages and that they were constrained by the tradition of their own madhhab in ways that earlier jurists had not been.

By the eleventh and twelfth centuries, Sunni jurists had come to accept the role of probability in legal interpretation. In the absence of clear scriptural prooftexts, the individual jurist, after exhaustive investigation of a legal question, professed that answer that was preponderant in his mind. This opinion did not rest on certitude (yaqin) but on strong presumption (ghalabat al-zann). Although it was not guaranteed to be correct, the mujtahid was not held to have sinned for coming up with the wrong answer as long as he had investigated the topic exhaustively, and the lay petitioner was permitted to perform his religious obligations according to this opinion. Probable answers to legal questions acquired authority in the absence of a certain answer.